The coefficient ofx103 in (1+x+x2+x3+x4)199.(x−1)201 is
Find the coefficient of x15 in (x3+x6+x9+...........)(x2+x4+x6+...........)(x+x2+x3+..........)
If x+1x=3, calculate x2+1x2,x3+1x3 and x4+1x4.